Perhaps you should try some spelling variations:
communication conversational » communication conversation, communication international, computation conversational
conversational case » conversational code, conversational cbr, conversational hand
case decision » cases decision, case decisions, care decision
decision a » decision _, decision aid, decision game

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: communication conversational case decision a (openg or open)~.
• If you are trying to use Boolean operators, they must be ALL CAPS: communication conversational case decision a (openg OR open).
• Adding a wildcard symbol may retrieve word variants: communication conversational case decision a (openg or open)*.